ITC VerifyNow System Platelet Reactivity Test - Manual (Page 96)

Appendix - 11
Page 92 14439.C 03/2013 VerifyNow System User Manual | USA
procedures or changing instrument parameters).
• As an additional security feature, various instrument display screens may be set to time out after
a default time period set by Accumetrics (2 to 5 minutes), or a time period set by the user (from 0
to 255 minutes). If the instrument is idle for a longer period, it will automatically return to the Main
Menu and require re-entry of User ID if applicable.
• The laboratory may decide to assign a Patient ID to each patient sample, to allow traceability of test
results. If this option is selected, the laboratory defines the format (number of characters) for the
Patient ID number and the VerifyNow Instrument will not accept a patient sample without entry of a
Patient ID in the designated format.
• Electronic Quality Control: The Electronic Quality Control (EQC) is the primary quality control
mechanism for the VerifyNow Instrument. It is a re-usable device that is inserted by the operator
into the test port and is used to perform a comprehensive testing routine that confirms performance
of the following key VerifyNow Instrument subsystems.
• Verifies proper performance of instrument optics.
• Confirms proper functioning of the pneumatics system that draws the sample into the test device
and moves it into the test device for reaction and measurement.
• Monitors reagent mixing parameters and sample data acquisition.
• Confirms correct calibration parameters.
• Simulates testing at two levels of results, to check correct data acquisition and calculations.
Specifically, the EQC measures two levels of turbidimetric signal that verify the dynamic range of
the instrument. One of these signals is at the level that would be observed in a patient with
a minimal amount of platelet aggregation (Negative or Low Level Control), and the other
represents a patient who demonstrates a significant amount of aggregation (Positive or High
Level Control).
• The required EQC testing frequency is input into the VerifyNow Instrument by the user. Accumetrics
recommends that the EQC be run at least on a daily basis, although the institution may select their
preferred EQC testing frequency. When the established interval has elapsed, the user is locked out
from running a patient test until the EQC test has been successfully completed.
• When run according to Accumetrics’ recommendations, the EQC meets CLIA requirements
for daily QC of the instrument system.
• System Controls for Each Sample Tested: Each time a test device is run on the VerifyNow System,
the instrument verifies the device expiration date, sample filling, optics performance, correct fluid
transfer, and proper mixing. The system controls prevent the operator from running an expired test
device. The system also detects certain other operator errors, such as placing the test device or the
sample in the instrument at the wrong time, or removing the test device before the test is complete.
These controls prevent reporting of an inaccurate test result. These controls exceed the CLIA
requirement for daily QC because they are performed for each test device.
11.9.1.2 VerifyNow Test Device
• Test Device Internal Controls: Each test device incorporates two levels of quality control to identify
invalid test runs caused by random errors, reagent degradation or inappropriate blood samples.
Before platelet activation and fibrinogen binding begin, the Negative (Aspirin) or Low-Level (P2Y12
and IIb/IIIa) Internal Control performs a test for non-specific aggregation. During the active phase
of the test, the Positive (Aspirin) or High-Level Internal Control channel monitors the reaction and
calculates Clinical Control Units, which must fall within specified limits. A failure of either internal
control results in an error message by the VerifyNow Instrument, which prevents the reporting of an
inaccurate result.